Berberine compounds are a series of isoquinoline alkaloids having varied therapeutic uses and importance. Many of these alkaloids may be found extensively in plants. Berberine compounds have been prepared through many synthetic pathways, including the Bischler-Napieralski cyclization. During a Bischler-Napieralski cyclization, an additional saturated ring is formed by intramolecular cyclization through an imidoyl intermediate. In most Bischler-Napieralski cyclization reactions, phosphorus oxychloride or phosphorus pentachloride are used as the cyclization reagents. Bischler-Napieralski Cyclization reactions, however, typically require undesirable reaction conditions (e.g., extremely high reaction temperatures) and produce berberine compounds in relatively low yield. Because of the potential therapeutic value of berberine compounds and derivatives thereof, there is a need for efficient synthesis processes for their preparation.